v3.26.1
Vanguard Long-Term Investment-Grade Fund Expense Example - Retail Prospectus [Member] - Vanguard Long-Term Investment-Grade Fund
Jan. 31, 2026
USD ($)
Investor Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 22
Expense Example, with Redemption, 3 Years 68
Expense Example, with Redemption, 5 Years 118
Expense Example, with Redemption, 10 Years 268
Admiral Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 10
Expense Example, with Redemption, 3 Years 32
Expense Example, with Redemption, 5 Years 56
Expense Example, with Redemption, 10 Years $ 128